Abstract: There is provided an information recording and reproducing method and an apparatus for the same capable of optimizing the shift adjustment of a recording pulse recorded in an optical disk even at the time of recording information on the optical disk at a high speed. The shift adjustment value of the recording pulse optimized at a low speed recording on an optical disk is multiplied by a constant value to be taken as the optimum shift conditions of the recording pulse at the high speed recording.

Abstract: An apparatus for controlling discrete data in a disk overwrite area or a power calibration area comprises a signal-processing unit, an address-processing unit, a control signal-processing unit, a clock recovery circuit, a signal-processing unit parameter control unit, and a clock recovery circuit parameter control unit, wherein the control signal-processing unit uses a message produced by a data on the disc to determine the control signals such as hold, load, or increasing bandwidth for holding, loading, and increasing the bandwidth of the parameters for processing the related circuits (such as the circuit of the signal-processing unit or the clock recovery circuit) of the discrete data produced between the two data clusters, so as to increase the convergent speed of the circuits for assuring the accuracy of reading data.

Abstract: Where a clock frequency based on which encoding is performed has deviated over time, problems such as that an appropriate digital signal can not be outputted occur. To solve the problems, it is arranged such that when a decoder decodes video data and audio data, a control variable for controlling a frequency of a clock recovered by a clock generating portion is recorded as needed in a recording portion, and when the decoder decodes data recorded in the recording portion, the clock generating portion is controlled by using the control variable so that system time information generated by the counter synchronizes with time information extracted upon reception of a digital broadcasting program.

Abstract: An optical disk apparatus includes a signal detection unit which detects a signal corresponding to a wobbling guide groove formed on an optical disk, a timing signal generating unit which generates first and second timing signals in accordance with an amplitude level of the signal detected, a photodetector which detects reflective light from the optical disk, and a wobble signal generating unit which outputs as a wobble signal a signal which is amplified with a low gain amount by the first timing signal in a case where an arithmetic signal, which is generated for the wobble signal on the basis of a signal detected by the photodetector, is at a high amplification level, and outputs as the wobble signal a signal which is amplified with a high gain amount by the second timing signal in a case where the arithmetic signal is at a low amplification level.

Abstract: An apparatus includes a read/write head disposed on a slider, a control circuit disposed on the slider, and an adjustable delay line disposed on the slider. The adjustable delay line delays transmission of aligned write data to the read/write head by an adjustable delay. The adjustable delay is controlled by the control circuit a function of read synchronization data provided by the read/write head.

Abstract: An optical disk recording method for recording predetermined data on an optical disk on the basis of a first reference clock signal used for recording, the optical disk including a groove track having a wobble signal recorded thereon and a land track having a land pre-pit carrying track position information, the first reference clock signal being generated on the basis of the wobble signal reproduced from the optical disk, includes the steps of reproducing a pre-pit signal from the optical disk; generating a second reference clock signal from the pre-pit signal; detecting an amount of phase shift of the first reference clock signal using the second reference clock signal; and correcting the first reference clock signal on the basis of an average value of the detected amount of phase shift.

Abstract: An optical disk as disclosed herein includes, among other things, a summing module that sums a compensation signal to a predetermined signal in a servo loop. The compensation signal compensates for a periodical disturbance input into a servo system of the optical disk device in units of a rotation angle of the disk rotating module. A phase lead imparting module imparts a predetermined amount of phase lead to an output signal from an optical detector module and outputs the predetermined amount of phase lead as the compensation signal. The predetermined amount of phase lead is determined in accordance with the rotation period information. The optical disk device performs an accurate iterative learning control to provide stable servo performance. The iterative learning control is performed such that the signal having imparted an optimal amount of phase lead in accordance with the rotation period information is added to the servo loop.

Abstract: A system for increasing storage capacity of an optical medium includes a demodulator module and a writing module. The demodulator module demodulates a wobble signal having a wobble period of N channel bits, has a demodulating period of M channel bits, and generates a phase error signal, where N and M are integers greater than 1, and M is greater than N. The writing module writes M bits on the optical medium during the wobble period of the N channel bits based on the phase error signal.

Abstract: Disclosed is a disc drive apparatus. The disc drive apparatus includes a rotational driving unit rotating a disc-shaped recording medium having a plurality of addresses recorded on an information recording surface of the disc-shaped recording medium; an optical pickup recording and/or reproducing an information signal on the information recording surface of the disc-shaped recording medium rotated by the rotational driving unit; and a control unit controlling rotation of the disc-shaped recording medium via the rotational driving unit. In the disc drive apparatus, the control unit carries out a disc constant velocity rotating processing that sets a predetermined address out of the plurality of addresses as a constant velocity rotation address and continuously reproduces the constant velocity rotation address using the optical pickup.

Abstract: There is provided an optical information recording/reproducing apparatus capable of obtaining a high super-resolution effect using an optical information recording medium in which a super-resolution thin film is formed. An optical information recording medium 1 having a super-resolution layer is irradiated with a laser light in a light emission pattern such that a bias light emission portion that does not cause the super-resolution layer to be in the state of super-resolution and a pulse light emission portion that causes the super-resolution layer to be in the state of super-resolution alternatively appear, and reflected light is detected. A reproduction signal based on the pulse light emission portion and a reproduction signal based on the bias light emission portion are acquired.

Abstract: Herein disclosed a phase difference detection apparatus for detecting a phase difference between a first signal and a second signal, which may include a waveform equalization section configured to input the first and second signals as a target waveform and an input waveform, respectively, to perform a waveform equalization process using a FIR filter so that the input waveform may coincide with the target waveform; and a phase difference detection section configured to perform a predetermined calculation based on predetermined tap coefficients of the FIR filter in the waveform equalization section to calculate an asymmetric component of the tap coefficients of the FIR filter thereby to detect the phase difference between the first and second signals.

Abstract: Digital audio can be transferred between a portable media player and an accessory. In one embodiment, an interface protocol is used to determine the sample rate capabilities of an accessory, allowing digital audio data for a track to be transmitted to the accessory at a sample rate supported by the accessory. When the sample rate of an audio track is not supported by the accessory, the media player can convert the sample rate of the track to a rate supported by the accessory and transmit the track after conversion. The media player also can use the interface protocol to inform the accessory if the sampling rate should be changed, e.g., due to tracks having different sample rates. The accessory then can send a request to the media player to change the sample rate. The media player then can transmit the digital audio data using the new sample rate.

Abstract: There is provided an optical disc recording apparatus containing a small-area circuit that is adaptable to both of the formats of DVD-R/RW and +RW/+R standards. The apparatus is provided with a circuit (106) for converting a 32T-cycle binarized wobble signal based on the +RW/+R standard into a 186T-cycle binarized wobble signal based on the DVD-R/RW standard, and the converted 186T-cycle binarized wobble signal is selected with a selector (108) during +RW/+R recording while the 186T-cycle binarized wobble signal is selected during DVD-R/RW recording, whereby subsequent PLL circuits are shared to reduce the circuit scale.

Abstract: The length of a format modulation area in an address segment is limited to be 25% of the address-segment length or less, and the position of the format modulation area is selectable two possible positions. Subsequently, where a CLV optical-disk medium is used, wobble modulation areas in adjacent recording tracks do not overlap each other in the radius direction.

Abstract: An embodiment of the present invention provides a phase difference detection circuit for detecting a phase difference between input data and an input clock generated based on the input data, including: an input data edge position detecting part detecting an edge position of the input data based on an N-phase clock obtained by dividing a predetermined period into N areas (N is an integer of 2 or more); an input clock edge position detecting part detecting an edge position of the input clock based on the input clock and the N-phase clock; and a phase difference detecting part detecting the phase difference between the input data and the input clock based on the edge position of the input data and an edge position of the input clock.

Abstract: The present disclosure can provide a method and an apparatus to correct wobble phase slip in an optical disc recording system during recording. The method of correcting a phase slip can include receiving a wobble signal of a first frequency, sampling the wobble signal to generate a sampled wobble signal, where the wobble signal is sampled at a second frequency that corresponds to a frequency of a sampling signal, comparing a phase of the sampled wobble signal with a phase of a controlled signal to generate a phase error, modifying the phase error by adding a phase bias, and adjusting the second frequency based on the modified phase error to reduce a magnitude of the modified phase error.

Abstract: An information reproducing method includes the steps o of reading information from an information medium that is rotated, and determining a rotation velocity of the information medium on the basis of a data transfer rate based on a specification of a read request.

Abstract: A method and apparatus for recording data at specific locations on a DVD includes selectively detecting the occurrence of wobble sync during a window computed from previous occurrences of wobble sync and eight-to-fourteen modulation sync. The method and apparatus also uses a phase-locked loop to recover the wobble signal, including wobble sync, and computes phase drift between wobble sync and eight-to-fourteen modulation sync and applies a compensation profile, compatible with a read clock phase-locked loop, to the wobble phase-locked loop.

Abstract: A PLL circuit includes a wobbling detector for detecting a wobbling signal based on reflection light of an optical disk having a wobbled track, and a VCO that an oscillation frequency of its output varies according to its input. The PLL circuit controls the VCO based on a phase error between the output of the wobbling signal and the output of the VCO. In the PLL circuit, the phase error is detected by executing an arithmetic operation to the delta-sigma modulated wobbling signal at a predetermined clock and the output of the VCO.

Abstract: Disclosed herein are aspects of optical tape technology, tape manufacturing, and tape usage.

Abstract: An apparatus for accessing data from a disc with a linking area comprises a pick up head, a servo, a processing unit, a position predictor, and a control signal generator. The pick up head reads data from the disc and generates a read signal. The servo controls the pick up head. The processing unit processes the read signal and controls the servo according to a plurality of control signals. The position predictor tracks time position on the disc and generates position information. The control signal generator receives the position information and generates the control signals according to the position information.

Abstract: One embodiment of an equalizer circuit has an FIR filter 116 in the asynchronously oversampled domain with a filter coefficient adaptation module that adapts the filter coefficients to the transfer function of a data read channel. Applications include tape drives, drives for optical and magnetic discs as well as receivers. The filter adaptation is performed on the basis of an error signal delivered by a slicer 128 which operates on synchronous samples after timing recovery and sample reconstruction.

Abstract: A method and system for automated discovery of logical network elements in a communications network speeds up and reduces the cost of discovering network elements and mapping network topology of network inter-connections. The method comprises the steps of building a cache of protection mechanisms in the communications network, building a network graph based on physical links of the communications network, traversing the network graph, comprising the step of, at each vertex of the network graph, determining whether there is a deterministic path that leads to a next vertex of the network graph, performing a depth first search on the network graph to determine connected components of the network graph, and creating the logical network elements based on the connected components of the network graph.

Abstract: A recording method for an optical disk drive is implemented as follows. First, at least one of the level of the focusing error signal, the level of the tracking error signal, a wobble synchronization pattern loss, the error rate of demodulating a wobble signal and the frequency of buffer under-run occurrence is detected. If at least one detected value exceeds the preset value, the recording will be ceased. Then, the rotation speed of the optical disk drive is decreased, and the recording is resumed with the decreased rotation speed.

Abstract: A demodulator for demodulating an input signal including a predetermined modulated signal includes a multiplication fundamental wave generator for outputting a multiplication fundamental wave for the predetermined modulated signal, a calculator for multiplying the multiplication fundamental wave by the input signal and for integrating the multiplication result, a demodulated signal generator for generating a demodulated signal of the modulated signal using the output from the calculator, a phase determiner for determining a cross-phase state of the input signal and the multiplication fundamental wave on the basis of a balance of levels of a plurality of integrated values, obtained as the integration result, for an interval containing the modulated signal in the input signal, and a phase adjuster for adjusting a phase of the multiplication fundamental wave to be supplied to the calculator on the basis of the determination result of the phase determiner.

Abstract: A phase measurement system for measuring phase between an input signal having a frequency and a reference signal having a substantially different frequency includes: a phase comparator having an output representing a time between a crossing of a first threshold by a clock derived from the reference signal and a predetermined time along an interval from a first sample to a second sample, where the input signal crosses a second threshold on the interval; an interpolator having an output indicative of an interpolated time of the second-threshold-crossing on the interval in the input signal; and a phase calculator which computes the phase difference by combining the phase comparator output and the interpolator output.

Abstract: A recordable optical disc (1, 1?, 1?, 100) comprises at least one user data area (12) for storing user data, and at least one controlling data area (6, 8, 10, 11) for storing controlling data necessary for accessing stored user data and/or for recording user data into a user data area (12), wherein at least a part of the physical structure of the optical disc corresponding to at least a part of at least one controlling data area (6, 8, 10, 11) and/or to at least a part of at least one user data area (12) has a modified physical structure (118, 120, 122, 123) which is arranged such that a standard optical disc recorder cannot record user data into at least a part of at least one user data area and/or controlling data area (6, 8, 10, 11).

Abstract: The present invention relates to an optical recording apparatus that provides improved writing speed. The apparatus has processing means (50) for processing an encoded data signal (NRZ) with a channel clock frequency signal (CLK). A first clock generator (52) derives a sub-sampled clock signal (CLKn) that has a lower frequency than the channel clock frequency signal (CLK). Furthermore, a modulator (MOD) modulates the sub-sampled clock signal (CLKn) with the encoded data signal (NRZ), and outputs a single, combined data and clock signal (NRZ_CLKn). This signal is received by the optical pick-up unit (OPU; 20), where a second clock generator (24) extracts a retrieved clock signal (CLKr) from the combined signal (NRZ_CLKn), and a data demodulator (23) extracts the encoded data signal (NRZ) using the retrieved clock signal (CLKr). Thereby, a fast and reliable bandwidth in the communication between the processing means and the optical pick-up (OPU; 20) is obtained.

Abstract: An information reproduction device capable of a more appropriate frequency monitoring of a read clock, as compared to conventional devices, is realized.

Abstract: A method and apparatus for writing data to a rewritable ultra-speed disc using an optimum pulse at a write speed of the disc, based on Absolute Time in Pre-groove (ATIP) information. The method includes: reading a disc code from the disc; determining a write speed of the disc from the read disc code; and writing data to the disc. The writing is at the determined write speed and according to a write strategy when the write strategy for the lead-in area is determined to be present, and is according on a default write strategy when the write strategy for the lead-in area is determined not to be present.

Abstract: To provide a disk reproducing apparatus capable of reading data at a lower error rate without requiring a complicated circuit configuration. An embodiment of the present invention provides a disk reproducing apparatus for reproducing a data signal based on a signal read from a disk and having a clock cycle that is an integral multiple of a cycle of a reproduction clock, including: a clock generating unit generating the reproduction clock based on an input signal obtained by binarizing the signal read from the disk; an error component detecting unit detecting an error component in the input signal; a threshold storage unit storing a threshold value for determining the error component; and a data signal reproducing unit reproducing the data signal in the input signal based on the error component detected by the error component detecting unit and the threshold value stored in the threshold storage unit.

Abstract: An optical disk drive is designed to read and/or write data from/on a spiral string of tracks where land and groove tracks are alternated. The drive includes: a light source for radiating a light beam; a lens for converging the light beam; a mechanism for moving the lens; a photodetector for generating an electrical signal based on at least a part of the light beam reflected from the optical disk; and a control section for controlling the light source and the mechanism responsive to the electrical signal. While performing a seek operation by having the lens moved by the mechanism such that a target track, from/on which the data should start being read or written, is irradiated with the light beam, the control section tries to get a PLL locked by irradiating another track, which precedes the target track by at least one, with the light beam.

Abstract: The MTD has some problems. Firstly, even if an input bandwidth is widened to obtain a larger SNR gain, an increase in the SNR gain cannot always be obtained due to the clock jitter that increases clock noise. Secondly, noise is sometimes superimposed on the clock supplied to an ADC when a transmission path connecting a clock-signal source to an ADC has a certain distance or when a certain form of mounting these members is employed. The noise lowers the performance. Provided is an optical disc apparatus including: a means for regulating loosely the bandwidth of a pulsed read signal; a means for boosting high-frequency components of a waveform of a driving signal of a laser diode; and a means for synchronizing autonomously a driving clock of the ADC and a DAC with a clock of the pulsed read signal.

Abstract: When receiving the reproduced data from the optical disc and buffering same, the buffering from the correct position can be started on the basis of the synchronous signal and the address information included in the sub data which was received simultaneously. There is provided a method for controlling the buffering of the main data which is reproduced from the optical disc, in which the main data and the sub data are received with taking word clocks which are partitioning timings having plural bits of the main data as a unit as references, a synchronous signal which is in synchronization with the main data is generated, and the buffering of the main data is started on the basis of the synchronous signal.

Abstract: A playback apparatus plays back information from a recording medium having a data structure including sync signals added in units of data items each having a predetermined size. The information is recorded in runlength limited codes, and the signals correspond to consecutive unique run lengths. The apparatus includes an information reading unit that obtains a binary data string as read information by reading the medium, a sync detection unit that performs detection of sync signals from the data string, and a data demodulation unit that obtains played-back data from the medium by performing demodulation on the data string with timing based on the detected signals. On the basis of detection, from the data string, of one detection pattern among types of detection patterns set as patterns including at least one of the unique run lengths, the sync detection unit regards the pattern detection as the signal detection.

Abstract: When performing writing and/or reading of information to/from an optical disk provided with a wobble including time axis information, an occurrence of a reading error of the time axis information from the wobble is suppressed so that disabled reading of information from the optical disk and an occurrence of a writing error can be prevented. Evaluated parameters such as a CRC error rate of an ATIP signal, an FMDT jitter amount and a phase error between an ATIP synchronization signal and a frame synchronization signal of writing data are evaluated based on a range of set values. When the evaluated parameter is deviated from the range of set values, writing and reading speeds are changed, thereby increasing the reading accuracy of the wobble signal.

Abstract: An optical disc apparatus includes an emitter which emits a laser beam to a optical disc, a divided photodetector including a first dived portion and a second dived portion disposed in a light path of the reflected beam from the optical disc, and producing a first photodetector signal and a second photodetector signal, a phase difference detector which produces a phase difference signal from a phase difference between the first and the second photodetector signals, an integrator which produces a integral signal from a integration of the phase difference signal, a tracking controller configure to perform tracking control based on the integral signal, and a limiter which limits a signal to be supplied from the divided photodetector to the phase difference detector or a signal to be supplied from the phase difference detector to the integrator based on a detection status of a signal detected by the dived photodetector.

Abstract: There is provided an information reproduction apparatus that can suppress degradations in the qualities of reproduced data and timing from due to interpolation errors when performing interpolation timing recovery, and that can avoid degradation in the stability of the system due to an increase in the timing recovery loop delay. An information reproduction apparatus (100) for reproducing data and timing from an analog signal including data information and timing information is provided with an expected value generator (106) for outputting plural expected values, and a maximum likelihood detector (107) for outputting data that corresponds to a sequence of the highest likelihood with an output sequence of an A/D converter among the plural expected value sequences, at the timing of a second clock.

Abstract: In an apparatus and method for checking a network synchronization clock signal in a communication system, the apparatus generates a divided clock signal which is the same as an externally inputted network synchronization clock signal, compares the value of one period of the network synchronization clock signal to the value of one period of the divided clock signal, and determines whether the network synchronization clock signal is normal or not. Thus, the reliability of an operation of checking the network synchronization clock signal is enhanced.

Abstract: A method and system for interleaving storage of data streams on a rotating storage medium of a data storage device comprise dividing the storage medium into a plurality of logical zones. Each logical zone of the plurality of logical zones extends radially from an inner diameter of the storage medium to an outer diameter of the storage medium. Data from a first stream of data is written to a first logical zone of the plurality of logical zones for up to an amount of time corresponding to the rotational speed of the storage medium and the size of the first logical zone.

Abstract: A method for recording data on a recording medium having one or more recording layers. The method includes reading control information including a plurality of control information units for controlling recording/reproducing of data from the recording medium. The control information unit includes a recording speed, an identifier of the recording layer, and a write strategy information depending on the recording speed, where a sequence of the information units is ordered according to the recording speed. The method further provides for recording the data on the recording layer based on the read control information unit including the identifier of the corresponding recording layer on which the data is to be recorded.

Abstract: An information signal is read from a recording medium to generate a reproduced signal. A sync detector detects a sync signal in the reproduced signal on a pattern search basis during operation in a direct mode. The sync detector sets a detection window and detects a sync signal in the reproduced signal in the detection window during operation in an inertia mode. A special pattern signal in the reproduced signal is detected and counted to generate a count result. The count result is reset in response to detection of a first special signal in the reproduced signal. A detection flag is generated in cases where a second special signal in the reproduced signal is detected when the count result denotes a last sector in a block of the reproduced signal. The sync detector changes its operation from the inertia mode to the direct mode when the detection flag is generated.

Abstract: A pattern of an input sync signal is compared with sub patterns in a first sync pattern. The sub patterns in the first sync pattern are equal to the patterns of true sync signals, respectively. When the pattern of the input sync signal agrees with none of the sub patterns in the first sync pattern, the pattern of the input sync signal is compared with sub patterns in a second sync pattern. The sub patterns in the second sync pattern have temporal fluctuations with respect to the patterns of the true sync signals. Each of the sub patterns in the second sync pattern is assigned to only one of the true sync signals. It is determined that a sync signal is detected when the pattern of the input sync signal agrees with one of the sub patterns in the first and second sync patterns.

Abstract: A method and apparatus for recording information with improved capabilities of suitably updating numerous setting items addressing the change in recording velocity of an optical disc caused during information recording. The method for recording on the surface of the optical recording disc by a laser beam emanated from a light source, comprises, in case when a recording velocity changes during an operation of recording information, the step of selecting setting items out of a plurality of items, in which the setting items may affect to a degrade recording quality with the change in the recording velocity and the plurality of items are used for determining the shape of pulsating laser beam; identifying a set of the items to be updated including the setting items; and updating the set item by item to values suitable for the present recording velocity at a predetermined time interval while continuing the operation of recording information.

Abstract: Reproduction signals which are simultaneously obtained from an Ach head 3 and a Bch head 4 are time division multiplexed by a signal layout converting circuit 9 and arranged. An HPF unit 12 and an LPF unit 14 of a waveform equalizing circuit 16 are optimally switched on the basis of sync adjustment information such as switching information of the heads. An edge detection pulse width of an edge detecting circuit and an output frequency of a VCO 23 are controlled on the basis of the sync adjustment information. The output frequency of the VCO 23 is used as a clock signal of the reproduction signals by a signal processing unit 27 at the post stage.

Abstract: A reproducing apparatus includes a reading unit configured to generate a reproduced signal containing information data recorded in a track using a reflected light of an optical beam, a clock generation unit configured to generate a clock having a frequency associated with a wobbling cycle of the track, and a control unit configured to detect a phase difference between the reproduced signal and the clock, and to control the clock generation unit using the phase difference detection result.

Abstract: A sampling rate for extracting information encoded on an optical disk is determined. First and second instances of a signal representing data encoded on the disk is detected, from which a disk rotation speed is determined. Based on the disk rotation speed, a sampling rate is determined.

Abstract: An optical disc (200) according to the present invention has a recording area divided into 28 zones of from a zone Z0 to a zone Z27. In a given zone, the number of waves of a wobble is set so as to be equal, that is, the number of waves of the ADIP carrier is set so as to be equal, between optional two neighboring turns of the track or between optional two neighboring tracks. This achieves inphase-outphase matching on an average, for decreasing a WPP signal, so that such an optical disc may be provided in which no low frequency components are superposed on push-pull signals, even though the optical disc is of such a type in which the track pitch is narrower than 1.6 ?m, such as 1.25 ?m, or in which a mark is detected by DWDD from a groove, as in the case of the next generation MD2.

Abstract: A rotation control apparatus which can maintain an accurate rotating state even in a high density optical disk (DVD) having a structure such that parts of the sync signal are recorded at an interval different from that of the other sync signal parts. The apparatus has: a unit period signal generator for generating a period signal of a unit period; a pre-pit detector for detecting a pre-pit from the DVD; a phase difference detector for detecting a phase difference between the detection timing of the pre-pit and the unit period signal; and a holding circuit for holding the phase difference detected. The rotation of the DVD is controlled on the basis of the phase difference held at the holding circuit.

Abstract: An optical disk structure and optical disk recorder which enables data to be rewritten onto the recording layer of the optical disk. A clock reference structure is permanently formed along servo tracks of the optical disk. An optical transducer is coupled to the clock reference structure and generates a clock reference signal simultaneously with writing new data onto the recording layer of the optical disk. The data is written as data marks along the servo tracks. Each of the data marks includes edges. The edges of the data marks are recorded in synchronization with a write clock. The write clock is phase-locked with the clock reference signal. Therefore, the edges of the data marks are aligned with the clock reference structure with sub-bit accuracy. Standard DVD-ROM disk readers are not able to detect the high spatial frequency of the clock reference structure.